Egg conveyor belts are used to transport eggs from the barn or nesting areas to a processing station, for example a packaging station, in egg-producing operations. In this context, an egg conveyor belt within the meaning of the description and the following claims is any conveying system that can transport eggs. In particular, these are endless conveying systems which are typically designed as endless conveyor belts and can consist of a plastic material. Other embodiments of conveying systems can be metal rods, linked chains, grids or grates.
A typical conveying system to collect eggs from several areas of a barn or to transport these eggs to one or several processing stations consists of a plurality of longitudinal conveyor belts, which run parallel to each other and on which the eggs are transported from the nesting areas directly from the livestock area of the egg-producing animal and one or more cross conveyor belts. Typically, the cross conveyor belts run vertically to the running direction of the longitudinal conveyor belts and transport the eggs conveyed from the longitudinal conveyor belts to the processing station.
A special problem in the transport is that egg production is naturally irregular and only to a certain extent statistically predictable, but cannot be predicted in its amount and timely distribution in the individual case, for example in regard to a longitudinal conveyor belts. Consequently, the collection of the eggs is operated by means of the conveyor with different amounts of eggs which have to be transported and, thus, different stocking density of the belts. In this context, stocking density means a stacking density, i.e., a parameter of the conveying process that is measured by the number of eggs per unit area.
Another specific problem of egg conveying systems is the fact that the structure of the eggs is extremely sensitive to damage. While the majority of eggs have a firm shell that is loadable to a certain extent, among the collected and transported eggs are also a small number of eggs with a thin shell, which are extremely sensitive to loads. Eggs, which are exposed to high conveying forces during the conveying process can be damaged and thereby cause contaminations of the conveying machinery, which, in turn, bring about additional problems through bonding effects. This applies in particular to eggs with very thin shells. For example, in the course of the conveying process, eggs are particularly sensitive to creating jams, in which the eggs cause high horizontal forces among themselves and which can result in damages to individual or multiple eggs.
EP 1 856 971 B1 specifies a counting apparatus which counts the eggs transported on a conveyor belt through line-by-line scanning. This counting apparatus is also described for the purpose to control a conveyor belt based on the counting result in such a way that a predetermined number of eggs is transported. It showed, in practice, that such a control of the conveyor belt in many conveying situations results in a transport that is free of damages based on needs; however, in some conveying situations a smooth operation of the conveyor belt cannot be avoided and thus poses the danger of damaging the eggs.
The problem of the irregular conveying process on the one hand and the dangers of damages on the other hand, in particular, has problematic effects on processing stations in regard to the control and adjustment behavior of such conveying systems. It is usually desired to generate a continuous flow of eggs at such processing station to be able to operate the processing station efficiently. While such a continuous flow of eggs in the area of the end of the conveying system leading into the processing station would best be solved with a jam of eggs formed in this location and its slow and continuous retrieval through the processing station, due to the danger of damages when transporting the eggs, this is not a practical solution.
The invention is based on the object to provide an egg conveyor belt which makes it possible to control an egg conveyor belt in such a way that while more reliably avoiding damages to eggs achieving a higher conveying rate or such with fewer interruptions than is known in prior art.